The vector systems described in this article have been used for inhibition of tumor growth. It will be discussed an appiications of non-viral vector systems with plasmid DNAs. The characteristics of the developed viral vector systems have been also summarized in this article. Most clinical trials employing retroviral vectors in present involve the administration of target cells transduced ex vivo. Although the majority of these studies is using retroviral vectors for gene transfer, there have been developed direct administration of vectors. One of them gene delivery by an electroporation method to transfer non-viral plasmid DNAs were compared with other transfer methods. In vivo electroporation electric pulses delivery in vivo can achieve the electropermeabilization of the cells in a tissue and allows hydrophilic substances to pass into the cell. Also, the selection of the expression promoters utilized in non-viral vector design are important things for transgene expression. We have examined the relative merits of introducing anti-oncogene ribozymes for cancers with these applications. And this method has been effectively transfered the plasmid DNAs into tumor. Thus in future our gene delivery system with theribozyme and the electroporation method as the drug will be used for cancer therapy.
